type Student = {
    name: string;
    gender: string; // 需求：只能取 男，女
    // gender: "男" | "女"; // 需求：只能取 男，女
    score: number;
    height: number,
    study: ()=>void,
    play?: ()=>void
}

let stu1: Student = {
    name: '小花',
    gender: '女',
    score: 100,
    height: 160,
    study: ()=>{}
}

let stu2: Student = {
    name: '小白',
    gender:"男",
    score: 100,
    height: 170,
    study: ()=>{}
}
